docs: def unstack(df, level=-1, reset_index=True):
      """pd.DataFrame.unstack adapter.
  
      Call the `df.unstack` method using the indicated level and afterwards
      join the column names using an underscore.
  
      Args:
          df (pandas.DataFrame): DataFrame to unstack.
          level (str, int or list): Level(s) of index to unstack, can pass level name
          reset_index (bool): Whether to reset the index after unstacking
  
      Returns:
          pandas.Dataframe: unstacked dataframe
      """
      df = df.unstack(level=level)
      if reset_index:
          df = df.reset_index()
          df.columns = df.columns.map(_join_names)
  
      return df